Related Field
The present invention relates to a base cut assembly applied to a sugar-cane harvesting machine.
Description of Related Art
Mechanization in sugar-cane harvesting has been employed in the agricultural field in the past few decades as an alternative to manual harvesting. Besides the fact that manual harvesting constitutes a dangerous work for the life of an agricultural worker, the efficiency of this type of harvesting is inferior to that of mechanized harvesting.
With a view to achieving rapidity and efficiency in handling the harvested cane, sugar-cane harvesting machines have been developed for simultaneously cutting and processing the cut sugar-cane. These machines comprise various elements, such as: tip-cutter, helical lift, row-divider, tumbling roller, base cut assembly, lifting rollers, conveying rollers, cutting rollers, elevators, husk extractors (among other components), which have specific functions in sugar-cane processing, from harvest to transport and transfer, the vehicle that follows this machine during the harvesting.
An important component on the harvesting machine is the base cut assembly, the function of which is to receive the bundles of sugar-cane after the latter have been inclined by the tumbling roller of the machine. The base cut assembly is a mechanism that is arranged flush with the ground, emerging from the machine floor toward the plantation ground. The base cut assembly should cut as close to the ground as possible, so as to prevent waste of unharvested cane left on the ground. However, the base cut assembly may also not allow its cutting elements (its metallic blades) to come touch the plantation ground, because, if it does to, its blades may wear off or even break due to the abrasion which they undergo in contact with the particulate present in the soil.
The base cut assembly is connected—either directly or indirectly—to a vertical actuator, which is configured for promoting alteration in height of this component with respect to the soil. The control over vertical movement, that is, control of the height of this mechanism, is carried out in the command cabin of the harvester. When the machine operator notices an obstacle ahead of the harvesting machine (for example, a stone or a termite-hill), he activates an electronic command for raising the base cut assembly temporarily.
The prior-art base cut assembly is composed by two cutters, which rotate flush with the ground, cutting the bundles of sugar-cane at the plant base, before they penetrate into the harvesting machine. Each base cut assembly rotates inside a bearing, the function of which is to anchor the cutter axle to a raising roller table. This association between the base cut and the raising roller table may be viewed in document BR MU8600817-0 of Dácio Helene Junior.
An alternative configuration consists of the solution proposed in document BR PI1107149-4 of Deere & Company. In this prior-art configuration, the base cut assembly is fixed to a structure called “main frame”, a movable structure that is arranged between the chassis and the operation cabin of the machine.
One of the problems of prior-art base cut assemblies is that their technology makes it very difficult for the harvester operator to control the height of the base cut disc. This is because from the operation cabin of the machine it is not possible to see all the unevenness of the ground. Besides, it is unfeasible to suggest that this operator should go through an entire plantation with his hands on the height control of the base cut disc, actuating this height control at every minor alteration present in the soil of this plantation. This causes this base cut assemblies now to leave unharvested cane in the plantation (wasting crop material) now to bump their blades with the plantation soil upon encountering unevenness in the plantation soil, damaging these elements and blunting their cutting edges.
Besides this disadvantage, the prior-art base cut assemblies are anchored onto the harvesting machine by means of bearings provided with a robust, resistant and heavy structure. These bearings are necessarily robust because they support the axle by contact with only one of its ends and the central part of the axle, leaving much of this piece free from contact with the bearing structure. When, for instance, a stone present in the soil hits the base cut disc, the force of this collision is multiplied by the whole extension of the free axle until it dissipates under the robustness of the bearing at the other axle end. By the low of linear moment, the larger the axle area exposed out of the bearing (that is, the longer the moment arm) the more resistant and heavier this bearing must be. Hence the robustness and high weight always present on the prior-art bearings.
However, the weight of an element comprised by an agricultural machine implies directly two drawbacks: increase in the total weight of the machine and the increase of its total manufacture cost. The latter is due to the fact that the heavier the component the more raw-material is employed to manufacture it.
It is also known that the total weight of an agricultural machine interferes directly with the compaction of the soil of a plantation. When this compaction occurs routinely, it may damage the plant routs and decrease the number of harvests capable of being carried out in the same plantation.
Thus, the prior art does not comprise a base cut assembly that is light, inexpensive, and is still capable of adapting to harvesting on uneven grounds, preventing waste of unharvested sugar-cane and damage to the metallic blades by accidental collision of this element with the plantation soil.